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Emergency water, salt and mineral calculator
Work out drinking water for a household, then table salt, potassium chloride, magnesium, and calcium for the same number of days.
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Where the amounts come from
The default water line is one US gallon, 3.8 litres, per person per day. That is the Ready.gov planning figure for drinking and basic hygiene. The other choices are 3 litres for drinking and cooking, or 5 litres for hot weather or heavy work. Every person counts, including children.
Salt is the table salt that contains the US reference sodium for the ages and sexes you enter (about 1,500 mg sodium a day for an adult, which is roughly 3.8 grams of salt). The tool also shows potassium chloride that contains the reference potassium, magnesium citrate at about 16 percent magnesium, and calcium carbonate at about 40 percent calcium. Age bands are simplified from the US dietary reference intakes. They are shopping quantities for a store, not a dose to swallow.
How to plan the liquids and the salt
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Step 1
Count people and days for water
Pick the litre figure that matches the situation you are storing for.
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Step 2
Add age groups for minerals
Two adults is the start. Add children as their own rows so the salt figure drops with age.
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Step 3
Choose a container
The table turns the litre total into bottles, 5-gallon jugs, jerrycans, or barrels.
Water and salt questions
Does the gallon include washing?
Ready.gov describes one gallon per person per day as enough for drinking and basic hygiene, not for laundry or a daily shower.
Should I take the potassium chloride as listed?
No. The grams are the amount of potassium chloride that contains the reference potassium for those people and days. How anyone uses a supplement is a medical question, not a calculator question.
How long does stored tap water last?
Keep it sealed, cool, and dark, and rotate it. The calculator sizes the volume. It does not treat dirty water.
Related
Water and salt are easy to forget because they are not a meal.